The automatic innervation of the eye is being defined by histochemical methods. Through use of the histofluorometric technique for catecholamines and the acetylcholinesterase technique for cholinergic innervation, the distribution and occurence of adrenergic and cholinergic nerves in the eye of various species is being studied on a comparative basis. In addition, the intrinsic innervation of the retina is also being studied.